Implantable devices, such as implantable medical devices, are increasing in complexity while shrinking in size. One hurdle to achieving such small and highly functional devices is the challenging ability to efficiently power these devices for a significant period of time. In particular, many implantable devices operate from power sources that have a limited lifetime and cannot be recharged, such as a non-rechargeable battery. After the device is implanted within the human body and the battery dies, the implant often must be removed. Thus, extending life of a battery of an implantable device is highly desirable.